A happy ending life to me would come to mean a life that had a bit of a rough or unsatisfying start. It got better and then you were satisfied. If you could speak as you were dying you would say you had a good end or life.
Oh yes even some of the best relationships can have rough patches and bumps. It is not that bad because it shows they can overcome obstacles and withstand the weather. It is not possible that all those stories that say they lived happily ever after then never encounter any problems.